Introduction to ZigBee
Getting started with your smart home can be confusing. There’s a mess of information out there but nobody seems to explain how it all works together. Nothing is worse than spending your hard-earned cash on a device that can’t be linked to your existing setup. If you want to make sense out of this mess and avoid costly mistakes, you’re going to want to have a solid understanding of the basics, including ZigBee.
This article aims to clear up some misconceptions about what ZigBee is and what it does. After reading this, you should be well on your way to knowing what devices will work for you and how to incorporate them into your home.
Don’t feel like you have to memorize all this information in one go. Feel free to bookmark this page and use it a reference when needed. This article will be kept up to date and if you can’t find the answer you’re looking for, leave a comment and we will happy to help you out.
If you are looking for something specific, feel free to skip ahead using the table of contents above.
Why Do We Need ZigBee?
In the last few years, there has been an explosion in smart devices. It seems like just about every week new devices are hitting the market, each competing for the next spot in your smart home. The problem arises when trying to get all these devices to talk. How can I be sure my smart lights will turn on when I unlock my back door? Not all devices have an app and even if they did, using a separate smartphone app to control each device sounds like a nightmare. This is where ZigBee comes to the rescue.
So What is Zigbee and What Does it Do?
Zigbee is a way for devices to talk to each other. It’s essentially a “language” that allows devices speaking it to communicate with each other, even if they come from different manufacturers. Since these devices speak a common language, there is no barrier to communication. This is known as a protocol. Since all of these devices follow the guidelines laid out in the protocol, your ZigBee compatible smart light bulbs can be told to turn on when you flip a ZigBee compatible light switch. Plus, it is a low-cost and low-powered mesh network (we’ll get to all that later) which makes it perfect for the kind of sensors you would use in your home.
What is the ZigBee Alliance?
The Zigbee Alliance was established in 2002 as a group of companies committed to maintaining and publishing the ZigBee standard. In fact, the name ZigBee is a trademark of this group. The technical standard is actually IEEE 802.15.4, not quite as catchy. This group publishes policies and guidelines allowing manufacturers to create products that can communicate with each other. As long as your device follows the standard and policies, it will be able to communicate with any other device following the same standards. Over 500 companies currently members and more are joining every day. If you’re interested in learning more about the ZigBee alliance, be sure to check out their website.
There are three types of devices that can exist in the ZigBee system:
- ZigBee Coordinator
- ZigBee Router
- ZigBee End Device
The coordinator is the most advanced device in the list. It “orchestrates” the communication between other devices by receiving and transmitting data between them. Every ZigBee network is required to have one coordinator to act as the root of the network. The coordinator can also act as a bridge to other networks, like WiFi.
A ZigBee router functions in the same way as the router connecting you to the internet. The router is a network device that passes data around the network. I know this sounds a lot like a coordinator, but a router is not, “in charge” the way a coordinator is.
ZigBee End Device
The end device is the simplest of all devices. It’s only role is to talk to the parent node. The parent node can be either a coordinator or a router. Since the device doesn’t need to continuously be talking, it spends most of its time in a sleep state, conserving battery. In addition to conserving power, end devices are the least advanced and therefore the cheapest to manufacture. This makes them ideal for use in smart home networks.
ZigBee architecture uses a mesh network. A mesh network transmits data by hopping node to node. If a node to node connection is broken or becomes unreliable, the network will detect it and begin repair using a self-healing algorithm. This makes mesh networks very reliable since there are always multiple paths from a sender to a receiver.
What Kind of Range does ZigBee Get?
Alright, now we’re getting to the good stuff. If we want our home to be connected, we are going to have to make sure our devices are connected. So how far can the ZigBee signal be sent? According to the ZigBee Alliance, ZigBee 3.0 can communicate up to 75-100 meters indoors.
This is an impressive range that should be suitable for any home. As long as each device is within range of another device, the signal can hop. If device A wants to talk to device C 150 meters away, it can send the message to device B, located in the middle, 75 meters away. The signal can then be sent from device B to device C. This is called signal hopping. If you are dealing with a situation where the standard range is not enough, you can use range extenders to increase the maximum distance between devices.
ZigBee vs. Bluetooth vs. WiFi vs. Z-Wave
With so many ways to communicate, it’s important to understand the differences between them. Since we are focusing on ZigBee in this article, we will compare and contrast the differences between ZigBee and the other popular protocols.
ZigBee vs. Bluetooth
We can compare, ZigBee and Bluetooth, but in reality, they are not actually competitors. Each aims to solve a different problem.
Bluetooth aims to form a persistent connection between devices. It uses much larger packets to transmit data. This allows large amounts of data to be sent between two devices, eliminating wires. Bluetooth works great for pairing hands-free devices to your phone or sending a file from your computer to a Bluetooth printer. The downside of this is high power consumption, resulting in the need to replace or recharge batteries more frequently.
As discussed earlier, ZigBee uses low power and sends small packets containing less information. Since the role of ZigBee is focused more on home automation, there is no need to trade battery life in order to send larger packets. This makes ZigBee much more suitable for home automation needs, although some devices do offer Bluetooth functionality. For instance, a smart deadbolt lock may use a Bluetooth connection between itself and your phone. This connection allows the deadbolt to be unlocked based on a command sent from the phone.
ZigBee vs. WiFi
Similar to Bluetooth, WiFi and ZigBee are not thought of as competitors. They both form networks albeit with small differences. Whereas ZigBee focuses on a mesh network, WiFi uses a star network topology. This means that all devices connect to the central hub. When connecting to your WiFi, each device has to independently connect to the router. There is no signal hopping like that occurring in ZigBee networks. This makes WiFi highly dependent on a strong signal meaning your devices must all be close to the central router. This is a problem when dealing with home automation. Unlike a laptop or smartphone, smart devices cannot always be moved closer to the router.
Like Bluetooth, WiFi has high bandwidth allowing for the transfer of large amounts of information. This is great for things like streaming Netflix or checking your email. However, this is bad for battery life.
WiFi still has a role in home automation though and you will see it used in many applications.
ZigBee vs. Z-Wave
This is where things start to get interesting. Although Bluetooth and WiFi aren’t considered competitors to ZigBee, Z-Wave absolutely is. Most people new to home automation stumble when trying to decide between the two. At times it can feel like the most important decision you will make, “Every choice from this point forward will depend on what I do now!” Let me start by putting your mind at ease:
The decision between Zigbee & Z-Wave isn’t as difficult as people make it seem. Both networks make heavy use of a hub and many hubs on today’s market support both protocols. Don’t put off the joy of building your own smart home by stressing over this decision!
There, now that that’s out of the way we can continue with our comparison. Both ZigBee and Z-Wave are mesh networks. Zigbee can technically handle up to 65,000 connected devices. Bandwidth issues would likely prevent anybody from actually achieving this number in reality. Z-Wave is limited to handling 232 devices. Both of these networks should easily handle most residential smartphone applications.
With ZigBee, there’s no limit to the number of “hops” data can travel. This is great for larger homes. Z-Wave, on the other hand, is limited to four hops. This means Z-Wave will be slightly more restrictive in its applications.
Both ZigBee and Z-Wave use AES-128 standard for encryption. This doesn’t mean these networks are completely hack-proof but seeing how this is the same encryption used by banks, you probably shouldn’t be too worried.
If ZigBee outperforms Z-Wave on the number of devices it can handle and the number of nodes data can hop through, why would you ever choose Z-Wave? Well, Z-Wave outshines ZigBee when it comes to reliability. More specifically, Z-Wave operated on the 800-900 MHz range of frequencies where ZigBee 3.0 operates on the 2.4GHz. If that 2.4GHz number sounds familiar it’s because that is the same operating frequency of WiFi networks. This, in turn, can cause a lot of interference leading to reliability problems. Here in the US, ZigBee is capable of running on the 915MHz frequency. This might solve the problem with interference, but it creates a new one. Switching to this lower frequency causes the data transmission rate to fall from 250kbps to 40kbps, a substantial decrease that many may not be happy with.
In the end, neither one is inherently better. If you already have a hub, you should use whichever one your hub is compatible with. If you are just starting, you should consider getting a hub that is capable of handling both. This would solve the issue entirely, leaving you to select the device you prefer without the need to worry so much about protocols.
If you are considering using ZigBee you must be aware of the compatibility between the most common devices.
Is Google Home Compatible with ZigBee
Unfortunately for Google Home users, Google Home is not directly compatible with ZigBee devices. You’re not completely out of luck though. A hub such as Phillips Hue Bridge or Smartthings Hub can act as a middleman and relay messages from your device to your Google Home. When using a Google Home and considering ZigBee devices, be sure to factor in the hub. It might bump the cost up initially, but one hub is usually sufficient for all of your devices.
Is Amazon Alexa Compatible with ZigBee
The new Echo Show and Echo Plus are both compatible with ZigBee. This means you will be able to directly link your ZigBee compatible devices to your Amazon device. Although there is no direct need for a hub, the Echo Show and Echo Plus can still connect to ZigBee certified hubs such as the Samsung Smartthings hub or the Wink hub.
Is Apple Homepod Compatible with ZigBee
Similar to Google Home, Apple’s HomePod is not directly compatible with ZigBee products. If you wish to connect your ZigBee devices to your HomePod, you will need to make use of a hub. Phillips Hue Bridge, Samsung Smartthings, and Wink are all compatible and will give you the option to control your ZigBee devices using Siri.
If you already have a home hub you will want to make sure it’s compatible with ZigBee before purchasing any ZigBee devices. Common hubs supporting the ZigBee protocol are the Wink Hub 2, Samsung SmartThings, the Almond 3, Phillips Hue Bridge, and the Vivint Smart Home.
If you are looking for the ultimate compatibility solution and don’t mind going the DIY route, you can always build your own hub. It isn’t as difficult as it sounds, and we have step by step instructions located here. Going this direction also allows you to use Home Assistant to manage all of your devices and gives you the complete freedom to fully customize your smart home.
If you are building your smart home hub using an Arduino, you can attach a module giving your hub the ability to communicate with ZigBee devices. The XBee Shield hooks up directly to your Arduino. From here, an XBee Antenna can be connected. Now your Arduino can act as a smart home hub for all of your ZigBee compatible devices.
Raspberry Pis are the most common DIY smart home hub. If you are using a Pi I suggest you use a USB dongle that allows for both ZigBee and Z-Wave connections. I am currently using the GoControl USB Hub. The good thing about this module is it allows for both ZigBee and Z-Wave devices to connect to the Pi rather than requiring a separate dongle for each networking protocol.
What Can I do with Zigbee Products
One of the benefits of ZigBee is the wide range of products available. Just about every category contains at least a few devices compatible with ZigBee. Depending on what project you are planning to tackle, here are a few that we prefer.
ZigBee Smart Outlets and Plugs
When it comes to ZigBee powered outlets, the Sylvania Smart Plug is by far my favorite. The power button located at the top of the plug allows you to turn on/off devices with a physical button in addition to a ZigBee connection.
ZigBee Light Switches and Bulbs
If you’re looking for smart bulbs ZigBee has you covered. For regular white bulbs, Sengled Smart bulbs are a good option but if you are looking for color, and not afraid to spend a bit more, nothing beats the color on Phillip Hue bulbs.
If you are looking to make your existing lights smart. The GE in-Wall light switch dimmer works great. The advantage of using a smart light switch is it will work with your existing bulbs. It can be expensive to purchase smart bulbs, especially for something like a chandelier. A light switch like this will give you control without the need to go buy a shopping cart full of new bulbs.
Custom projects may require something a bit more versatile. You can find a variety of ZigBee sensors to accomplish whatever you need. There are temperature and humidity sensors, liquid sensors to keep your home safe from leaks, vibration sensors to protect windows, open/close sensors to help with making your home more secure, motion sensors for indoor/outdoor lights, and more.
Where to Go from Here?
Hopefully, you should have a pretty good understanding and feel for ZigBee by now. It is easy to see why it remains one of the most popular network standards for use in your smart home. Whether you are just starting your smart home journey or are just looking for the next project, you should feel confident when making the decision to go with ZigBee.